This invention generally pertains to heterocyclic carbon compounds having drug and bio-affecting properties and to their preparation and use. In particular, the invention is concerned with various heterocyclic derivatives characterized by Formula I, infra., which are inhibitors of blood platelet aggregation.
The following patent is representative of United States patents relating to the pyrimidine heterocyclic carboxylic acid and ester derivatives disclosed herein in Field of Search 514/274 and 544/335. Caldwell, et al., U.S. Pat. No. 4,486,443 discloses hydantoins having antithrombogenic properties of formula (1). ##STR1##